The question of whether humans have discrete cognitive systems operating on different levels has been debated for years. Therefore the recent finding of J. David Smith (J. Psychological Science, February 2014) seems important to me, from the point of view of persistence of Aristotelian think among even leaders of physics – see my letter in our Bulletin, October 2009.
Anthony P. French (the author of “Newtonian Mechanics”) had contributed a letter in American J. of Physics (January 1984) title: Did Newton forget his own laws of motion? According to that letter, Newton wanted to reconsider some Aristotelian ideas again, when he was around 62. I think the difference in Newton’s own thinking is the result of different cognitive systems in his own mind. In addition, students’ *contrasting* answers to question of circular motion (John Warren, 1971) is also a result of different cognitive systems operating at different levels. Hence I think that David Smith’s investigation can be useful for physics educationists as well.